If you want to get out of Bitcoin, buy dollars or euros.
Buying fiat ist not a solution, at least not for everyone. The market cap of Bitcoin is in the billions of $$ and there is only a few good exchanges out there. Each exchange would sit on a billion dollars or more, too much, if you ask me. The risk is that exchanges may go out of business if Bitcoin forks, and then all the $$ are gone (or you have to file a bankrupcy claim MtGox style).
Withdrawing to bank accounts is tricky; in most countries banks ask lots of questions or freeze accounts if a customer receives too much money from a Bitcoin exchange. In the U.S. the taxman will ask questions too.
I doubt that whales would sell into fiat. Therefore I believe that money will flow out of BTC into other cryptos, if the fork goes wrong